The present invention relates to suspension systems and more particularly to a valve mechanism that permits pressure equalization between a negative gas spring chamber and a positive gas spring chamber when the pressure in the negative gas spring chamber exceeds the pressure in the positive gas spring chamber.
Typically, a suspension system includes an inner tube slidable within an outer tube and a compression or positive spring for biasing the inner and outer tubes apart from each other. The suspension system may further include a negative spring that counteracts the force of the positive spring by biasing the inner and outer tubes toward each other. The positive and negative springs permit the inner and outer tubes to compress in response to an impact and expand or rebound after the impact. The positive and negative springs may be formed from a variety of biasing elements such as coil springs, elastomer springs, leaf springs, air springs and the like. One drawback associated with gas springs is that gas may leak from the positive gas spring chamber to the negative gas spring chamber, resulting in a change in the overall spring characteristics of the suspension system. Another drawback is that the positive and negative gas spring chambers must be pressurized separately, thereby adding cost to the design by requiring an inflation valve for each of the springs. Additionally, with this configuration, the positive gas spring chamber must be pressurized before the negative gas spring chamber, further complicating the setup process. Accordingly, there is a need to provide a device that regulates the gas pressure between the positive and negative gas spring chambers and permits the use of a single inflation valve to pressurize both positive and negative gas springs.